U.S. Pat. No. 4,135,104 discloses a CCD (charge coupled device) regenerator circuit that overcomes the problem of gradual dissipation of charge associated with digital CCDs while also providing elemental logic and arithmetic functions. A standardized quantity of charge is injected along with charge less than a predetermined quantity into a potential well under a storge electrode arranged to retain only a predetermined quantity of charge. Overflow from the storage electrode represents charge in excess of the predetermined quantity. It is detected by a master electrode that controls a slave electrode. The slave electrode forms a shunt path for the predetermined quantity of charge and is normally maintained in a transfer state. The slave electrode shifts to a barrier state when the excess charge is present however, permitting the predetermined quantity of charge to advance along another electrode path. Consequently, when a quantity of charge representing an assigned binary value is applied to the regenerator circuit, a predetermined quantity of charge representing the same binary value is transferred out, without inversion. In the absence of a charge at the binary input indicating the alternate binary value, the charge under the storage electrode is directed out the shunt path. By appropriate use of additional input transfer electrodes and output transfer electrodes the regenerator circuit serves as a basic unit which can provide fundamental logical and digital functions needed in digital systems.